[Hallicrafters] Cleaning switches with aerosol

[Mike Everette]

I tend to agree, BE CAREFUL, and LESS IS MORE.  I had
a bad experience once with a Hammarlund HQ-180 which
developed an intermittent in the selectivity switch. 
That one is dense with parts and almost impossible to
"selectively" clean.  I sprayed the offending wafers,
rotated the switch around several times, etc and let
it dry for a couple of hours.  

When the receiver was powered back up, one switch
wafer arced over and was charcoaled, burned up beyond
any hope of repair.  The phenolic wafer had absorbed a
dose of the contact cleaner, which shorted it out to
ground through the metal switch framework.

Very fortunately, in this case I was able to replace
the switch.  That is, the COMPLETE assembly, prewired
with all components, which made life much easier!  At
one time it was still possible to obtain factory-stock
Hammarlund parts from the people who bought it all
when the plant in Mars Hill, NC closed; but sadly,
this source has been gone for a number of years now.

Imagine frying a switch in this fashion in an SX-28 or
(worse?) an SX-42 or (shudder) an SX-88?

Need I say more?

73

Mike
WA4DLF



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